So we should just ban anyone that has ever made a bad joke or made a sarcastic comment.
No, but we shouldn't turn a blind eye to it either. If no one ever calls someone on a bad joke, the joker will never know it was a bad joke and is likely to repeat it. This is a difficult decision we each need to make for ourselves. An innocent remark to one person can be deeply offensive to another. On the other hand, some people take offense very easily. There is no simple answer.
A personal example: I'm Jewish. I was born in Brooklyn in 1943. A large part of my extended family died in the Holocaust. Certain jokes about lampshades are not at all funny to me. Some people might see that as kidding around. I can't. Mostly I wouldn't say anything, but it would ***** just the same. To some people that is ancient history and no longer relevant. It isn't ancient to me.
I despise political correctness. I'm happy to occasionally root for the Washington Redskins and hold doors for women. However, I feel we should be aware of how what we say may be interpreted by others. We have as much of an obligation to avoid giving offense as we do to avoid taking offense. This media - messaging - makes it very easy to both give and take offense so we should take extra care. I'm sure we have all seen flame wars brew up over something that seemed very ***** at first.